Refastenable fastening devices of the hook and loop variety are currently widely used. Such refastenable fastening devices have been used in clothing, disposable articles, and various miscellaneous articles such as safety belts and the like. Such devices are used when it is desirable to create a refastenable bond between two or more articles or between several surfaces of the same article. In certain applications, these refastenable fastening devices have replaced conventional buckles, zippers, buttons, snaps, tie fasteners, and sewing.
A popular type of mechanical fastener currently in wide use which utilizes mechanical entanglement to create a refastenable bond is sold under the trademark "VELCRO". VELCRO fastening devices are described in greater detail in U.S. Pat. No. 2,717,437; U.S. Pat. No. 3,009,235; U.S. Pat. No. 3,266,113; U.S. Pat. No. 3,550,837; U.S. Pat. No. 4,169,303; and U.S. Pat. No. 4,984,339; among others.
VELCRO fasteners utilize two components, a male component and a female component. The male and female components are often referred to as the hook and loop components, respectively. The hook component consists of a fabric which contains a plurality of resilient, upstanding hook-shaped elements. The female component of the fastening device consists of a fabric containing a plurality of upstanding loops on its surface. When the hook component and the loop component are pressed together in a face-to-face relationship to close the fastening device, the hooks entangle the loops forming a plurality of mechanical bonds between the individual hooks and loops. When these bonds have been created, the components will not generally disengage under normal conditions. However, when a gradual peeling force is applied to the components, disengagement can be easily effected. Under a peeling force, since the hooks are comprised of a resilient material, they will readily open to release the loops.
While the VELCRO type of fastening devices have been found to be relatively useful on disposable diapers, disposable packages, cartons and the like, the use of such fastening devices on disposable articles has been limited due to the fact that such fastening devices are relatively costly to manufacture. The high manufacturing costs are typically associated with both the hook and the loop components of these devices.
Conventional hook and loop components of the VELCRO variety are typically formed by making a fabric with a number of woven loops extending outwardly from a backing. The loops may be provided by weaving a base fabric containing supplementary threads to form the loops, or by knitting loops into a fabric. In other hook and loop components, the loops may be formed by pleating or corrugating processes, where the loops are subsequently cut to form the hook components.
These processes generally produce costly hook and loop fastening materials because they are relatively slow. The hook and loop components of such fastening devices are also usually made out of the same relatively expensive material. This material is generally relatively expensive for the hook component because the material used in the hook component needs to be resilient so that the hooks can disengage from the loop component when the device is opened. Additionally, the material is generally relatively expensive due to the need of such material to be strong enough to hold the engaged hooks when subjected to forces applied on the fastening device.
Several attempts have been made to make alternative types of female components for fastening devices. However, such attempts have generally suffered from a number of drawbacks.
One such attempt is described in Ribich, et al. U.S. Pat. No. 3,708,833 issued on Jan. 9, 1973. The Ribich, et al. patent discloses a refastenable fastening device having a female component that comprises reticulated urethane foam secured to a backing layer. The female component disclosed in the Ribich, et al. patent suffers from the drawback that foams typically do not have enough openings for the hooks of conventional hook components to penetrate. Reticulated foam also does not have sufficient strength to hold such hooks when forces are applied to the fastening device. Further, manufacturing reticulated foam is a relatively expensive process.
Brumlik U.S. Pat. No. 3,905,071 issued on Sep. 16, 1975 discloses a "press-through self-gripping device." The device described in the Brumlik patent does not appear to be suitable for use in a refastenable fastening device that utilizes a conventional mating hook component with resilient hooks. The fastening device disclosed in the Brumlik patent is intended to be used for fastening one or more sheets of material between a gripping member and a receiving member. The gripping member disclosed in the Brumlik patent has rigid and stiff needle-shaped elements for gripping elements. These needle-like elements are particularly unsuitable for use in fastening devices on disposable absorbent articles. The disclosure of the Brumlik patent, thus, appears to be limited to the devices that employ gripping elements adapted to penetrate and pass through several sheets of material and lodge inside a receiving member.
Therefore, there is a need for a low-cost fastening device for disposable articles. In particular, there is a need for such low-cost fastening devices to perform in a manner comparable to the more expensive commercially-available fastening devices.
It is an object of the present invention to provide an improved low-cost female component for a fastening devices.
It is another object of the present invention to provide a female component for a fastening device that can be used with both commercially-available hook components having resilient individual hooks, as well as less expensive hook components with more brittle hooks than those currently in use.
It is further object of the present invention to provide a low-cost female component that makes more efficient use of materials than existing fastening devices and that utilizes reduced amounts of expensive materials.
It is still another object of the present invention to form a low-cost female component for a refastenable fastening device by stacking materials on top of one another which have certain desired individual characteristics for entangling and engaging the hooks of a mating hook component.
It is a still further object of the present invention to provide a low-cost and improved method for producing such a female component.
These and other objects of the present invention will be more readily apparent when considered in reference to the following description and when taken in connection with the accompanying drawings.